Sunday, March 11, 2007

One useful feature that subversion and many other Versioning Systems offer for developers is the ability to include keywords in text files stored in the repository.

These keywords get replaced when some action is done on them by the server. This book excerpt (reproduced below) documents some keyword supported by subversion.

The keyword to be replaced is identified by an anchor in the text with the keyword name surrounded by two '$keywordName$.

Subversion defines the list of keywords available for substitution. That list contains the following five keywords, some of which have shorter aliases that you can also use:

LastChangedDate

This keyword describes the last time the file was known to have been changed in the repository, and looks something like $LastChangedDate: 2002-07-22 21:42:37 -0700 (Mon, 22 Jul 2002) $. It may be abbreviated as Date.

LastChangedRevision

This keyword describes the last known revision in which this file changed in the repository, and looks something like $LastChangedRevision: 144 $. It may be abbreviated as Revision or Rev.

LastChangedBy

This keyword describes the last known user to change this file in the repository, and looks something like $LastChangedBy: harry $. It may be abbreviated as Author.

HeadURL

This keyword describes the full URL to the latest version of the file in the repository, and looks something like $HeadURL: http://svn.collab.net/repos/trunk/README $. It may be abbreviated as URL.

Id

This keyword is a compressed combination of the other keywords. Its substitution looks something like $Id: calc.c 148 2002-07-28 21:30:43Z sally $, and is interpreted to mean that the file calc.c was last changed in revision 148 on the evening of July 28, 2002 by the user sally.as in $keywordName$.

Have fun!

UPDATE on march/2009Normally it would be necessary to set the properties on every single file of your system so the replacement of these props would happen. However, there is an easier way to do this, which is set the auto-props property in your environment.

In folder "C:\Documents and Settings\[your_username]\Application Data\Subversion" you will find a file named config (with no extension). In this file there should be a property "enable-auto-props" commented out. Remove the comment from this line so it looks like this:

### Set enable-auto-props to 'yes' to enable automatic properties### for 'svn add' and 'svn import', it defaults to 'no'.### Automatic properties are defined in the section 'auto-props'.enable-auto-props = yes

Then, on the same file, find the section [auto-props] and add a line at the end. If you want the replacement to happen only in your java files, add this: